/* Reset & Base */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif; color: #1A1A2E; line-height: 1.6; background: #fff; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; height: auto; }
ul { list-style: none; }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* Navigation */
.navbar { position: fixed; top: 0; left: 0; right: 0; background: rgba(255,255,255,0.98); box-shadow: 0 2px 20px rgba(0,0,0,0.06); z-index: 1000; padding: 0 20px; }
.navbar .container { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.navbar-brand { display: flex; align-items: center; gap: 10px; font-size: 24px; font-weight: 700; color: #2563EB; }
.navbar-brand svg { width: 36px; height: 36px; }
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a { font-size: 15px; color: #4A5568; font-weight: 500; transition: color 0.2s; }
.nav-links a:hover { color: #2563EB; }
.nav-btn { display: inline-block; background: #2563EB; color: #fff !important; padding: 10px 24px; border-radius: 8px; font-weight: 600; font-size: 14px; transition: background 0.2s; }
.nav-btn:hover { background: #1d4ed8; }
.mobile-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; }
.mobile-toggle span { width: 24px; height: 2px; background: #1A1A2E; display: block; }

/* Hero */
.hero { padding: 140px 20px 80px; background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 50%, #eff6ff 100%); text-align: center; position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%; background: radial-gradient(circle at 30% 50%, rgba(37,99,235,0.05) 0%, transparent 50%); }
.hero h1 { font-size: 48px; font-weight: 800; color: #1A1A2E; margin-bottom: 20px; line-height: 1.2; }
.hero h1 span { color: #2563EB; }
.hero .subtitle { font-size: 20px; color: #4A5568; margin-bottom: 16px; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero .trust-badge { display: inline-block; background: rgba(37,99,235,0.1); color: #2563EB; padding: 8px 20px; border-radius: 50px; font-size: 14px; font-weight: 600; margin-bottom: 32px; }
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary { display: inline-block; background: #2563EB; color: #fff; padding: 16px 40px; border-radius: 12px; font-size: 18px; font-weight: 700; transition: all 0.3s; box-shadow: 0 4px 15px rgba(37,99,235,0.3); }
.btn-primary:hover { background: #1d4ed8; transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37,99,235,0.4); }
.btn-secondary { display: inline-block; background: #fff; color: #2563EB; padding: 16px 40px; border-radius: 12px; font-size: 18px; font-weight: 700; border: 2px solid #2563EB; transition: all 0.3s; }
.btn-secondary:hover { background: #eff6ff; transform: translateY(-2px); }

/* Section */
.section { padding: 80px 20px; }
.section-alt { background: #f8fafc; }
.section-title { text-align: center; font-size: 36px; font-weight: 800; margin-bottom: 16px; color: #1A1A2E; }
.section-desc { text-align: center; font-size: 18px; color: #64748b; max-width: 600px; margin: 0 auto 50px; }

/* Trust Section */
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; max-width: 1000px; margin: 0 auto; }
.trust-card { text-align: center; padding: 30px 20px; background: #fff; border-radius: 16px; box-shadow: 0 2px 15px rgba(0,0,0,0.05); }
.trust-card .icon { font-size: 40px; margin-bottom: 12px; }
.trust-card .number { font-size: 32px; font-weight: 800; color: #2563EB; }
.trust-card .label { font-size: 14px; color: #64748b; margin-top: 6px; }

/* Features */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.feature-card { padding: 36px 28px; background: #fff; border-radius: 16px; box-shadow: 0 2px 15px rgba(0,0,0,0.05); transition: all 0.3s; border: 1px solid #f1f5f9; }
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 8px 30px rgba(0,0,0,0.08); }
.feature-card .icon { width: 56px; height: 56px; background: #eff6ff; border-radius: 14px; display: flex; align-items: center; justify-content: center; font-size: 28px; margin-bottom: 20px; }
.feature-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { font-size: 15px; color: #64748b; line-height: 1.7; }

/* Platform */
.platform-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; max-width: 800px; margin: 0 auto; }
.platform-card { text-align: center; padding: 36px 20px; background: #fff; border-radius: 16px; box-shadow: 0 2px 15px rgba(0,0,0,0.05); transition: all 0.3s; }
.platform-card:hover { transform: translateY(-4px); box-shadow: 0 8px 30px rgba(0,0,0,0.1); }
.platform-card .icon { font-size: 48px; margin-bottom: 14px; }
.platform-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 12px; }
.platform-card .dl-btn { display: inline-block; background: #2563EB; color: #fff; padding: 10px 28px; border-radius: 8px; font-size: 14px; font-weight: 600; transition: background 0.2s; }
.platform-card .dl-btn:hover { background: #1d4ed8; }
.platform-note { text-align: center; margin-top: 30px; font-size: 16px; color: #64748b; }

/* Pricing */
.pricing-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; max-width: 900px; margin: 0 auto; }
.pricing-card { background: #fff; border-radius: 20px; padding: 40px 32px; box-shadow: 0 2px 20px rgba(0,0,0,0.06); border: 2px solid #f1f5f9; position: relative; }
.pricing-card.popular { border-color: #2563EB; }
.pricing-card.popular::before { content: '最受欢迎'; position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: #2563EB; color: #fff; padding: 4px 20px; border-radius: 50px; font-size: 13px; font-weight: 600; }
.pricing-card h3 { font-size: 24px; font-weight: 700; margin-bottom: 8px; }
.pricing-card .price { font-size: 42px; font-weight: 800; color: #2563EB; margin: 16px 0; }
.pricing-card .price span { font-size: 16px; color: #64748b; font-weight: 400; }
.pricing-card ul { margin: 20px 0 30px; }
.pricing-card ul li { padding: 8px 0; font-size: 15px; color: #4A5568; display: flex; align-items: center; gap: 10px; }
.pricing-card ul li::before { content: '✓'; color: #2563EB; font-weight: 700; }
.pricing-card .pricing-btn { display: block; text-align: center; background: #2563EB; color: #fff; padding: 14px; border-radius: 10px; font-size: 16px; font-weight: 600; transition: background 0.2s; }
.pricing-card .pricing-btn:hover { background: #1d4ed8; }
.pricing-table { max-width: 900px; margin: 30px auto 0; }
.pricing-table table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 12px; overflow: hidden; box-shadow: 0 2px 15px rgba(0,0,0,0.05); }
.pricing-table th, .pricing-table td { padding: 16px 20px; text-align: center; border-bottom: 1px solid #f1f5f9; }
.pricing-table th { background: #2563EB; color: #fff; font-weight: 600; font-size: 15px; }
.pricing-table td { font-size: 15px; color: #4A5568; }
.pricing-table tr:last-child td { border-bottom: none; }
.pricing-free { text-align: center; margin-bottom: 40px; }
.pricing-free a { display: inline-block; background: linear-gradient(135deg, #2563EB, #3b82f6); color: #fff; padding: 16px 48px; border-radius: 12px; font-size: 20px; font-weight: 700; box-shadow: 0 4px 15px rgba(37,99,235,0.3); transition: all 0.3s; }
.pricing-free a:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37,99,235,0.4); }

/* Steps */
.steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; max-width: 900px; margin: 0 auto; }
.step-card { text-align: center; padding: 30px 20px; }
.step-card .step-num { width: 64px; height: 64px; background: #2563EB; color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 28px; font-weight: 800; margin: 0 auto 20px; }
.step-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.step-card p { font-size: 15px; color: #64748b; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: #fff; border-radius: 12px; margin-bottom: 16px; box-shadow: 0 2px 10px rgba(0,0,0,0.04); border: 1px solid #f1f5f9; overflow: hidden; }
.faq-item details { padding: 0; }
.faq-item summary { padding: 20px 28px; font-size: 17px; font-weight: 600; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; font-size: 24px; color: #2563EB; font-weight: 300; transition: transform 0.2s; }
.faq-item details[open] summary::after { content: '−'; }
.faq-item .faq-answer { padding: 0 28px 20px; font-size: 15px; color: #4A5568; line-height: 1.8; }
.faq-item .faq-answer ol { padding-left: 20px; margin-top: 10px; }
.faq-item .faq-answer ol li { margin-bottom: 8px; list-style: decimal; }

/* Footer */
.footer { background: #1A1A2E; color: #94a3b8; padding: 60px 20px 30px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; max-width: 1200px; margin: 0 auto; }
.footer-brand { font-size: 24px; font-weight: 700; color: #fff; margin-bottom: 12px; }
.footer-desc { font-size: 14px; line-height: 1.8; margin-bottom: 16px; }
.footer h4 { color: #fff; font-size: 16px; margin-bottom: 16px; }
.footer ul li { margin-bottom: 10px; }
.footer ul li a { font-size: 14px; color: #94a3b8; transition: color 0.2s; }
.footer ul li a:hover { color: #fff; }
.footer-bottom { max-width: 1200px; margin: 40px auto 0; padding-top: 20px; border-top: 1px solid #2d3748; text-align: center; font-size: 13px; }
.footer-official { color: #2563EB; font-weight: 600; }

/* Responsive */
@media (max-width: 1024px) {
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-toggle { display: flex; }
  .hero h1 { font-size: 32px; }
  .hero .subtitle { font-size: 16px; }
  .section-title { font-size: 28px; }
  .features-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; gap: 20px; }
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-buttons { flex-direction: column; align-items: center; }
  .btn-primary, .btn-secondary { width: 100%; max-width: 300px; text-align: center; }
}

/* Page-specific */
.page-header { padding: 120px 20px 60px; background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%); text-align: center; }
.page-header h1 { font-size: 40px; font-weight: 800; margin-bottom: 12px; }
.page-header p { font-size: 18px; color: #64748b; max-width: 600px; margin: 0 auto; }
.content-section { padding: 60px 20px; }
.content-block { max-width: 800px; margin: 0 auto 50px; }
.content-block h2 { font-size: 28px; font-weight: 700; margin-bottom: 16px; color: #1A1A2E; }
.content-block h3 { font-size: 22px; font-weight: 600; margin-bottom: 12px; color: #2563EB; }
.content-block p { font-size: 16px; color: #4A5568; line-height: 1.8; margin-bottom: 16px; }
.content-block ul { padding-left: 0; margin-bottom: 16px; }
.content-block ul li { padding: 8px 0; font-size: 16px; color: #4A5568; line-height: 1.8; padding-left: 24px; position: relative; }
.content-block ul li::before { content: '•'; color: #2563EB; position: absolute; left: 0; font-weight: 700; }
.content-block ol { padding-left: 24px; margin-bottom: 16px; }
.content-block ol li { padding: 8px 0; font-size: 16px; color: #4A5568; line-height: 1.8; list-style: decimal; }
.guide-steps { max-width: 800px; margin: 0 auto; }
.guide-step { display: flex; gap: 24px; margin-bottom: 40px; align-items: flex-start; }
.guide-step-num { min-width: 48px; height: 48px; background: #2563EB; color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 20px; font-weight: 800; }
.guide-step-content h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.guide-step-content p { font-size: 16px; color: #4A5568; line-height: 1.8; }
.download-cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 800px; margin: 0 auto; }
.download-card { background: #fff; border-radius: 16px; padding: 32px; text-align: center; box-shadow: 0 2px 15px rgba(0,0,0,0.05); border: 1px solid #f1f5f9; }
.download-card .icon { font-size: 48px; margin-bottom: 14px; }
.download-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.download-card p { font-size: 14px; color: #64748b; margin-bottom: 16px; }
.download-card a { display: inline-block; background: #2563EB; color: #fff; padding: 12px 32px; border-radius: 8px; font-size: 15px; font-weight: 600; transition: background 0.2s; }
.download-card a:hover { background: #1d4ed8; }
@media (max-width: 768px) {
  .download-cards { grid-template-columns: 1fr; }
  .guide-step { flex-direction: column; }
  .page-header h1 { font-size: 30px; }
}
.about-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; max-width: 800px; margin: 40px auto; }
.about-stat { text-align: center; padding: 30px; background: #fff; border-radius: 16px; box-shadow: 0 2px 15px rgba(0,0,0,0.05); }
.about-stat .number { font-size: 36px; font-weight: 800; color: #2563EB; }
.about-stat .label { font-size: 15px; color: #64748b; margin-top: 6px; }
@media (max-width: 768px) { .about-stats { grid-template-columns: 1fr; } }